The present invention relates to a display device of the type which utilizes an emission of electrons into a vacuum space, which is defined between a front substrate and a back substrate; and, more particularly, the invention relates to a display device in which there are arranged, with high accuracy, cathode lines having electron sources and control electrodes, which control the quantity of electrons emitted from the electron sources, which display device can exhibit stable display characteristics by maintaining a vacuum between the front substrate and the back substrate.
As a display device which exhibits a high brightness and high definition, color cathode ray tubes have been widely used conventionally. However, along with the recent request for higher quality in the generation of images in information processing equipment or television broadcasting, there has been an increased demand for planar displays (panel displays), which are light in weight and require a small space, while exhibiting a high brightness and a high definition.
As typical examples, liquid crystal display devices, plasma display devices and the like have been commercialized. Further, as display devices which can realize a higher brightness, it is expected that various kinds of panel-type display devices, including a display device which utilizes the emission of electrons from electron Sources into a vacuum (hereinafter, referred to as “an electron emission type display device” or “a field emission type display device”), and an organic EL display device, which is characterized by low power consumption, will be commercialized.
Among such panel type display devices, there are various types of field emission type display devices, including a display device having an electron emission structure as developed by C. A. Spindt et al, a display device having an electron emission structure of a metal-insulator metal (MIM) type, a display device having an electron emission structure which utilizes an electron emission phenomenon based on a quantum theory tunneling effect (also referred to as a “surface conduction type electron source”), and a display device which utilizes an electron emission phenomenon observed with a diamond film, a graphite film and carbon nanotubes and the like.
The field emission type display device includes a back substrate, on which cathode lines having electron-emission-type electron sources and control electrodes are formed on an inner surface thereof, and a front substrate, on which an anode and a fluorescent material are formed on an inner surface which faces the back substrate; wherein, both substrates are laminated to each other by inserting a sealing frame between the inner peripheries of both substrates, and the inside space between substrates is evacuated. Further, to set a distance between the back substrate and the front substrate to a given value, distance holding members are provided between the back substrate and the front substrate.
The distance holding members for maintaining the distance between the back substrate and front substrate are formed of thin plates made of glass or ceramics, which are disposed in an erect manner at positions spaced from the pixels. Here, as conventional examples of a display device provided with such distance holding members, attention is directed to Japanese Unexamined Patent Publication 326306/1995 and Japanese Unexamined Patent Publication 338528/2001.